The relay containing a permanent magnet could be classified by motion modes of armatures, which could be divided into a rotating armature, a direct-acting armature, and so on. Wherein, a direct-acting relay (the relay with a direct-acting armature) is a very important class of relays. In addition, it has the features such as a simple structure, a broad application, and a stable performance. In particular, the direct-acting relay is widely used in aerospace, defense and civilian fields. In a direct-acting relay containing a permanent magnet, the permanent magnet provides the retention force in a stable state, the armature is the device to undertake a switching operation, and the yoke is the device to limit displacement of the armature. Based on the permanent magnet, the armature, and the yoke as a center, the entire relay magnetic circuit consisted of a connecting coil core, a magnetic permeable ring and other devices, directly determines the overall performance of the relay containing a permanent magnet.
Therefore, it becomes a demanding problem to be solved for those skilled in the art how to design an electromagnetic structure having a highly efficient magnetic flux confinement, bistable magnetic latching, low energy consumption of the coil, and a simple structure.